The free citizenship class at the Gaithersburg Library usually runs about 12 weeks, but Yeslis Martínez has come back every Tuesday for more than a year.

A permanent resident from El Salvador, Martínez filled out an application for naturalization last September. She got her fingerprints taken a few weeks later. Every day, she would study test questions and go online to check the status of her paperwork.

Now, she keeps waiting — and returning to the class in suburban Maryland — to practice for an interview she thought she would have had by last December.

“I felt so excited. I would think, ‘Yeslis, you’re going to become a citizen,” she said. “But it kept taking longer, and my spirit started to fall. . . . That feeling of hope just kind of stopped.”

Since President Trump announced his candidacy by denouncing illegal immigration and vowing to close off the southern border, there’s been a sharp spike in the number of permanent U.S. residents applying for naturalization.

But application forms doubled in length during the Obama years, with dozens of new questions about “good moral character,” and the Trump administration has been scrutinizing those documents more closely, advocates say.

The result is a growing backlog of citizenship applications at a time when Trump’s immigration crackdown has made even permanent residents feel like they may be at risk.

In 2014, the average application took about five months to go through the naturalization process. Now it takes almost twice that. In the past four years, the number of pending applications has more than doubled — it was 753,352 as of March 31, the most recent date for which data is available.

The backlog is especially pronounced in immigrant-heavy jurisdictions like Washington, D.C., and Maryland, where wait times can reach 16 or 17 months.

U.S. Citizenship and Immigration Services spokesman Michael Bars said his agency is “committed to adjudicating all petitions, applications and requests fairly, efficiently and effectively,” adding that the office is on track to approve more applications in 2018 than in any of the past five years.

Bars said that since applications surged — a trend that began under President Barack Obama — the agency has opened two new offices and expanded 10 others.

But Joshua Hoyt, director of the National Partnership for New Americans, an association of immigrant advocacy groups, said USCIS has not done enough to keep up with demand, calling the longer wait times a “second wall.”

“People are waiting in good faith for something that’s their right,” he said. “Backlog numbers have increased dramatically, and it appears that nothing has been done to reduce them.”

Citizenship applications tend to peak around presidential election years, and this past cycle was no different. But 17 months after Trump’s inauguration, numbers were still high compared with historical trends.

“For the most part, people are doing it now because they’re afraid,” Oh said. “It’s not that they want to vote in 2020. It’s that they want to protect themselves and their families, and the best way they can do that is through naturalization.”

Although Martínez has been eligible to apply for citizenship since 2016, she did not fill out an application until after the government announced it would terminate temporary protected status for Salvadorans. Her mother has TPS, and Martínez said she hoped that if she became a citizen, she could sponsor her mother.

One of her classmates in Gaithersburg, Leonida Alvarez, has had a green card since moving to the United States from Nicaragua in 1984. But she only recently decided to apply for citizenship, at the urging of her children. Experts say many other long-eligible permanent residents are doing the same.

It’s not just more applications, though. Experts and advocates say that more stringent policies and forms — instituted by both the Trump and Obama administrations — have prevented USCIS from meeting the growing demand.

In 2014, the office expanded its citizenship application form from 10 to 21 pages, including an expanded section on “good moral character.”

Applicants now must say, for instance, if they’ve ever been a member of an insurgent group, or if they’ve ever been involved with — or targeted by — genocide.

Yana Cascioffe, who coordinates the citizenship class in Gaithersburg through Baltimore City Community College, said these longer forms also have an effect on processing times: Because every question on the written application form must also be asked in person by a USCIS officer during the citizenship interview, sessions that used to take 30 minutes are now typically twice that long.

“USCIS is generally trying to be more vigilant and generally trying to pay more attention to every application and every detail,” Cascioffe said. “They’re definitely looking into people’s pasts more than they have before.”